爱华网现在很多人都会选择考研，考博等。下面是小编给大家整理的AAAAA，供大家参阅!
AAAAA：Cells and temperature
Cells cannot remain alive outside certain limits of temperature and much narrower limits mark the boundaries of effective functioning. Enzyme systems of mammals and birds are most efficient only within a narrow range around 37C;a departure of a few degrees from this value seriously impairs their functioning. Even though cells can survive wider fluctuations the integrated actions of bodily systems are impaired. Other animals have a wider tolerance for changes of bodily temperature.
For centuries it has been recognized that mammals and birds differ from other animals in the way they regulate body temperature. Ways of characterizing the difference have become more accurate and meaningful over time, but popular terminology still reflects the old division into “warm-blooded” and “cold-blooded” species; warm-blooded included mammals and birds whereas all other creatures were considered cold- blooded. As more species were studied, it became evident that this classification was inadequate. A fence lizard or a desert iguana-each cold-blooded----usually has a body temperature only a degree or two below that of humans and so is not cold. Therefore the next distinction was made between animals that maintain a constant body temperature, called home0therms, and those whose body temperature varies with their environments, called poikilotherms. But this classification also proved inadequate, because among mammals there are many that vary their body temperatures during hibernation. Furthermore, many invertebrates that live in the depths of the ocean never experience change in the depths of the ocean never experience change in the chill of the deep water, and their body temperatures remain constant.
AAAAA：Sleep
Sleep is part of a person’s daily activity cycle. There are several different stages of sleep, and they too occur in cycles. If you are an average sleeper, your sleep cycle is as follows. When you fist drift off into slumber, your eyes will roll about a bit, you temperature will drop slightly, your muscles will relax, and your breathing well slow and become quite regular. Your brain waves slow and become quite regular. Your brain waves slow down a bit too, with the alpha rhythm of rather fast waves 1 sleep. For the next half hour or so, as you relax more and more, you will drift down through stage 2 and stage 3 sleep. The lower your stage of sleep. Slower your brain waves will be. Then about 40to 69 minutes after you lose consciousness you will have reached the deepest sleep of all. Your brain will show the large slow waves that are known as the delta rhythm. This is stage 4 sleep.
You do not remain at this deep fourth stage all night long, but instead about 80 minutes after you fall into slumber, your brain activity level will increase again slightly. The delta rhythm will disappear, to be replaced by the activity pattern of brain waves. Your eyes will begin to dart around under your closed eyelids as if you were looking at something occurring in front of you. This period of rapid eye movement lasts for some 8 to 15 minutes and is called REM sleep. It is during REM sleep period, your body will soon relax again, your breathing will slip gently back from stage 1 to stage 4 sleep----only to rise once again to the surface of near consciousness some 80 minutes later.
AAAAA：醉驾
What a scary and sensational scene it is! In the drawing, the driver, as drunken as a fiddler①, is driving fast on the road, with a large bottle of beer on the top of his car. What is conveyed by the picture has both realistic and alarming implications for each member of the country。
The profound meaning of the vivid drawing can be elaborated in terms of both awareness of security and social responsibility. For one thing, consciousness of safety should be one of our top priorities. Life is one-way journey: you cannot experience it twice. So life is to be respected and awed②. It is cruel to and inhumane to spell the end of any life, with a careless driving under the influence (DUI)③. For another, to act as a responsible member of the society, each of us should bear social responsibility. We do not live only for ourselves but also for those whom we love and who love us. It is irresponsible to claim either lives of drivers or lives of other victims are not important, leaving the families and relatives into deep grief and, may be, great living burden④。
In short, it is imperative that legislative measures should be taken by the authority to punish drunk drivers severely such as suspending their driving licenses or even putting them into jail. Besides, the mass media, such as TV, radio and website, should work together to enhance awareness of security and sense of responsibility to reduce the rate of car accident。
AAAAA：大学生就业
As is vividly depicted by the drawing above, the job-hunting girl refuses a service post without any hesitation, complaining that she will never take a job of serving others①. At the same time she is wondering why finding a promising job is so difficult in modern society②。
This phenomenon can easily be found anywhere in our daily life③, especially on campus. On the one hand, many job-seekers are reluctant to take jobs that they consider to be humble and trivial, such as being a secretary or an assistant, because they have great ambitions and they only want to ride on the peak of success. What is amazing is that they are not conscious that ambition is to be achieved step by step④. On the other hand, wanting to gain more but pay less, both the jobless and graduating students aspire to seek a job that is well-paid, relaxed and comfortable. This kind of “no work, all play” attitude toward life can be destructive to both personal and social development. We should not look down upon service industry, the third industry, because it does provide us with many employment opportunities and positions⑤。
Therefore, it is high time that we took effective measures to improve the current situation. For one thing, an education campaign should be launched to popularize the idea that “the longest journey starts with a single step” and to cultivate a down-to-earth attitude toward life. For another, the tendency of being lazy must be eradicated from the mind of the young. Only in this way can people realize their value of life better and can unemployment rate be reduced and thus can social harmony be achieved
AAAAA：食物安全
Over the past couple of years, several cases of the food scandal have been disclosed on various media. The problem of food security has become a hot button across society. The prevalence of food insecurity has greatly impacted public health, which the government could not afford to ignore, according to the online edition of the People Daily.
There are a couple of driving forces, I would argue, behind this undesirable tide. First, in the course of the rapid economic evolution, we ignore moral education, giving rise to the rising rate of the problem. More importantly, the lack of adequate regulation and punishment on those illegal producers enforces the trend.
As Confucius instructed, it is better late than never. Prompt and strict measures should be taken to turn back this evil trend. The government should launch a massive moral campaign to educate all citizens and draw up tougher laws to crack down on those irresponsible corporations and prohibit them from entering the food industry again. I am firmly convinced that through our combined ef
以上是小编整理所得，欢迎大家阅读和收藏。
